Quote Originally Posted by phytokind
Cannabis likes moist soil and low humidity. Seedlings obviously like a higher humidity, but they don't remain seedlings for very long so I wouldn't try to increase the humidity, just keep the soil nice and moist.
I agree a hot dry climate is optimal.

If for some reason you DO want to bring up the RH, spraying is a great way to feed them and make them happy as well. If you are worried about being too rough, get household sprayers with a fine mist setting. For seedlings, clones and young plants they are quite good.